Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: parakorn on 24/01/2015 04:07:33

Title: What is the Hardest Branch in The theoretical Physics ??
Post by: parakorn on 24/01/2015 04:07:33
In present The hardest branch of physics if not include the superstring and the M theory   Does it was Quantum field theory or GR or other branch . Who know????
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 24/01/2015 06:52:41
Only Pete knows.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: alancalverd on 24/01/2015 08:56:23
The hardest branch of any physics is explaining it to other people.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: PmbPhy on 24/01/2015 12:52:44
Quote from: jccc
Only Pete knows.
Always the smartass, huh?

It can't be said that one branch is harder than another since what is difficult is a personal thing making the most difficult subject highly subjective.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: chiralSPO on 25/01/2015 04:05:10
It depends how you define "hardest"...

I think the mathematics associated with quantum mechanics is probably the most difficult--there are plenty of equations that are impossible to solve algebraically (though we can get numerical solutions or approximations for many of them, it just takes a supercomputer or cluster a few days or weeks of chugging...)

Though I think this applies to any complex system. Physics of many interacting bodies or many inter-related processes is bound to come up with some nasty equations.

But what about branches of physics that deal with very poorly understood problems? It seems like it would be pretty hard to study dark matter or dark energy, given how little we know about them...
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 25/01/2015 04:33:49
Please explain under what condition a positive charge able to circle/quantumdance a negative charge forever?
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: chiralSPO on 25/01/2015 04:46:06
jccc, we've been over this on many different threads. I can't tell you any more than I already have.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 25/01/2015 05:55:26
Please tell me something I can believe. Such as 2x3=6. Not 2 quantum 3 = 99.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: evan_au on 25/01/2015 05:57:15
An interesting question: "How can we travel faster than the speed of light?".
This is hard because currently popular theories forbid it (and theories allowing it are just speculation at this time).

A harder question: "What happens at & inside the event horizon of a Black Hole?"

What makes this hard is that (according to current theories), we can never find out what happens inside the event horizon.


Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 25/01/2015 06:50:05
The only black hole I find is in the toilet.

Just buy a car faster than light to travel faster than light.

Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: alancalverd on 25/01/2015 12:32:43
Please tell me something I can believe.

There's the problem. Physics is nothing to do with belief, only observation. See my reply #2 above.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: PmbPhy on 26/01/2015 06:12:52
Quote from: jccc
Please tell me something I can believe. Such as 2x3=6. Not 2 quantum 3 = 99.
What's the motivation for telling you something you can believe since when we tell it like it is you end up insulting the person trying to help you. Not to mention that nature does not work in a way which humans are supposed to believe. All it has to do is behave with an internal consistency.

If you really had an interest in learning physics rather than posting simple questions and expecting the answer to have a one line answer then read the following papers

http://home.comcast.net/~peter.m.brown/ref/what_is_science.pdf
http://home.comcast.net/~peter.m.brown/ref/philosophy_physics.pdf

That will give you a start on how physics actually works, rather than how you thought it works.

Then read the following - When physicists observe nature they observe patterns. We call these patterns Laws of Physics. When a law of physics is found then physicists make predictions using these laws. The laws are then tested in laboratory experiments. If the predictions are consistent with the results of the experiments then then the law is supported. Otherwise the law is either modified or tossed out.

Everything we've told you about quantum mechanics has been bourne out by experiments. Whether you believe it or not is of no consequence to nature or physicists.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 26/01/2015 06:59:00
What exact experiment proofs electron is circling the neutron?
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: PmbPhy on 26/01/2015 08:36:10
Quote from: jccc
What exact experiment proofs electron is circling the neutron?
Oy vey!

You really don't pay attention and you're too lazy to do the work required to find the answer to your problem. Recall what I said to you in my last post, i.e.
Quote from: PmbPhy
If you really had an interest in learning physics rather than posting simple questions and expecting the answer to have a one line answer then read the following papers

http://home.comcast.net/~peter.m.brown/ref/what_is_science.pdf
http://home.comcast.net/~peter.m.brown/ref/philosophy_physics.pdf
The very fact that you asked that question tells me that you didn't read those papers carefully. In fact you didn't read them at all.

I'll tell you a few things to get you on the road. First off you need to understand the postulates of quantum mechanics to even begin to have an understanding of the answer. Second, you need a solid understanding of the philosophy of physics to understand the relationship between experiments and the validity of the laws of physics. So far you not only have none of that buy you've shown absolutely no desire to start learning it. E.g. when did you ever ask a question on the philosophy of science or read an article or book on the subject?

Partial answer to your question: Electrons don't circle the nucleus of the atom. In fact in an hydrogen atom, with only a proton in the nucleus, there isn't even a neutron present. All physics can tell you is the probability of measuring the electron in a particular region of space around the nucleus. When measurements are made and recorded the measurements are consistent with what the Schrodinger equation predicts. The word "proof" has no place in physics. It never has and it never will. That's a common misunderstanding, one that you keep making.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 26/01/2015 08:56:27
The very fact that you asked that question tells me that you didn't read those papers carefully. In fact you didn't read them at all.

In fact I read both pages. First one said 3 things about science. Not too agree. Second page load too slow, I gave up.

Pete, do you really understand QM? Remember what einstan said? If you can't explain it to a six year old....
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 26/01/2015 09:09:59
An interesting question: "How can we travel faster than the speed of light?".
This is hard because currently popular theories forbid it (and theories allowing it are just speculation at this time).

A harder question: "What happens at & inside the event horizon of a Black Hole?"

What makes this hard is that (according to current theories), we can never find out what happens inside the event horizon.

I said it before, you don't remember.

A 100 mi/h train can not push a man travel faster than 100 mi/h.

The force we use to propulsion is em force, it has a speed limit. That's why faster than light speed traveling is impossible.

Not as einstain said, it is not the energy, the principle.   
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 26/01/2015 10:00:05
Electrons don't circle the nucleus of the atom. In fact in an hydrogen atom, with only a proton in the nucleus, there isn't even a neutron present. All physics can tell you is the probability of measuring the electron in a particular region of space around the nucleus. When measurements are made and recorded the measurements are consistent with what the Schrodinger equation predicts.

If electrons don't circle the nucleus, it has no momentum, it will fall in.

If electron don't circle the nucleus, how can iron can be magnetized? You know how many holes in QM?

U and D quarks carry opposite charges, so they should able to form groups without mysteryon?

I for 1 don't believe electrons circling at all, my theory is not welcome to you yet.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: PmbPhy on 26/01/2015 10:06:24
Quote from: jccc
In fact I read both pages. First one said 3 things about science. Not too agree. Second page load too slow, I gave up.
Come back when you read the second one, carefully.

Quote from: jccc
Pete, do you really understand QM?
Of course I understand it. I got all A's in my undergradute quantum mechanics courses and modern physics courses and B's in my graduate courses in quantum mechanics. And you? What did you study to get to the point where you are now in your understanding of quantum mechanics?

Quote from: jccc
Remember what einstan said? If you can't explain it to a six year old....
That was the most ridiculous thing he ever said. Especially in this day and age with the extremely difficult physics which are being discovered.

What part of my resonse didn't you understand? There is an equation in quantum mechanics called the Schrodinger equation. The solution to the equation is a wave function. The wave function is used to determine the probability of where the particle wil be found when you measure its location. There is nothing in quantum mechanics about particles moving. Therefore you cannot say that the electron circles or moves around the nucleus. The only way you can use quantum mechanics to talk about motion is to use an averaging calculation.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: PmbPhy on 26/01/2015 10:15:10
Quote from: jccc
If electrons don't circle the nucleus, it has no momentum, it will fall in. ...
Totally wrong. You keep using Newtonian mechanics to explain things in quantum mechanics. You can't do that. Quantum mechanics is a more fundamental theory and from that you can derive Newtonian mechanics and
predictions. You're trying to do it the opposite way.

You have an incredible amount of physics to learn before you tackle quantum mechanics but you're not willing to do that work. That's why you don't understand quantum mechanics and never will - until you do the basic work, from the ground up. I had to spend years learning algebra, trigonometry, calculus, vector analysis, mathematical physics, Newtonian Mechanics, Relativity, etc etc etc. It was then that I was prepared to learn quantum mechanics. You arrogantly think you can skip everything before quantum mechanics before you learn quantum mechanics.

The way you think it'll never happen.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 26/01/2015 10:30:54
Pete, everything is force, position, motion. The force between electron and nucleus has to be balanced to form stable atoms. What else is more fundamental?

Anyone can see the attraction force, only QM believers see the balance force.

Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: PmbPhy on 26/01/2015 10:46:58
Quote from: jccc
Pete, everything is force, position, motion.
The only thing about that is that position is part of QM. There is nothing in QM about force and motion (as you think of it, i.e. classically).

Quote from: jccc
The force between electron and nucleus has to be balanced to form stable atoms. What else is more fundamental?
The only thing that you'll see in quantum mechanics is the potential energy function.

See what I mean? All you're able to think about is classical physics. Every time you think about classical trajectories like a particle moving on a path you're no longer thinking about quantum mechanics.

I can see that you're at an impass and as such you'll never be able to grasp the concepts of quantum mechanics. As such I will no longer respond to any questions or comments by you. Especially with regards to any of these totally wrong comments like you just posted here. You're simply stuck in classical mechanics and are unable to get out of this rut you're in and since for some unknown reson you refuse to pick up a book on it and learn it I can't see trying to help someone who refuses to help themselves by reading and learning. Goodbye
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 26/01/2015 10:56:42
OK, you won again.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: PmbPhy on 26/01/2015 13:30:40
Quote from: jccc
OK, you won again.
I'm sorry jccc. I'm not really interested in winning anything. I'm only trying to help you understand quantum mechanics. I don't want to be or even sound  mean to you. However you don't appear to want to do the hard work to learn what you want to learn. Learning quantum mechanics is very difficult, regardless of what Einstein thought in that little quote.

If you were to look in almost any physics textbook you'll see in the preface a statement of what you need to have learned before you can read the text. There's a good reason for that.

In the preface of Introduction to Quantum Mechanics - Second Edition by David J. Griffiths, page viii the author states what the reader needs to know in order to understand the text
Quote
The reader must be familiar with the rudiments of linear algebra (as summarized in the Appendix), complex numbers, and calculus up through partial derivatives; some acquantance with Fourier analysis and the Dirac delta function would help. Elementary classical mechanics is essential, of course, and a little electrodynamics would be useful in places. etc.

Regarding objections to what I keep telling you, you're not alone. Everyone thinks that way at one time or another. As Richard Feynman once said
Quote
I think it is safe to say that no one understands quantum mechanics. Do not keep saying to yourself, if you can possibly avoid it, 'but how can it be like that?' because you will go 'down the drain' into a blind alley from which nobody has yet escaped. Nobody knows how it can be that way.

If nobody knows how it can be that way then what is it we're learning when we learn quantum mechanics? We're learning how to make predictions and to hopefully explain certain physical phenomena.
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: PmbPhy on 26/01/2015 15:49:06
jccc - In the event that you take our advice and read about physics then read the following book: Concepts of Modern Physics: The Haifa Lectures which you can download at:
http://bookzz.org/book/695697/7e974a
Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 27/01/2015 02:19:49
Good reading, thanks!

Title: Re: What is the Hardest Branch in The theoretical Physics ??
Post by: jccc on 27/01/2015 05:06:30
Pete, you could be a great lawyer. Seems you don't like $. Scientist make s little.

Database Error

Please try again. If you come back to this error screen, report the error to an administrator.
Back